Understanding the characteristics of research participants is crucial to ensuring sample representativeness and generalizability of findings to broader patient groups with substance use disorders. Using anonymous computer-administered health survey data, the present study had a unique opportunity to compare patients who chose to participate in an RCT for heavy/problem drinking or drug use (N=713; consenters) with those that chose not to participate (N=625; non-consenters). The sample was 40% male, 76% African American, and had a mean age of 45.2 years. Using multivariate regression, the most parsimonious model found older age, unemployment, prescription misuse, positive screen for drug problems (CAGE), having a grandmother with an alcohol problem, trouble falling asleep (past 30 days), health professional recommendation to go on a diet, and feeling unsafe due to a previous partner were all associated with consenting to participate. The present study provides benchmark data on sample representativeness in a clinical trial of SBIRT.

Protected forests need to be a representative selection of the natural proportion of forest types, including distribution of productivity levels, age classes and nature types This is important for the possibility to preserve biodiversity. In addition, the protected areas has to be of sufficient size and not isolated from each other, to function as effective biodiversity preservers. The question is, how does it look in reality? The objective with this study was to get an overall picture of the current forest protection situation in Östergötland, Sweden, and how it has changed the last 60 years. Are all ecologically relevant forest habitat types represented in appropriate proportions in protected forests? To evaluate where the protected areas are located in relation to each other, a connectivity index was calculated for each patch of protected area. Together with a value for size, a value index was created and applied to all protected areas, and it turns out that the protected areas of Östergötland is not totally representative when it comes to nature types, age classes and levels of productivity.For example, there is an underrepresentation of both pine and spruce forests on high-productivity soils. However, areas with higher productivity levels have been protected over time. The age distribution seems to be skewed towards older forests in protected areas. There are some underrepresented nature types, as well as overrepresented ones in nature reserves, a small overrepresentation of unproductive impediments, and only spruce and mixed forests seems well connected in the landscape. The greatest differences in protected and unprotected forests is the productivity level, were focus should be on protecting higher productivity areas in order to succeed in preserving the biodiversity of forests as intended.

No contexto da indústria mineral, reconciliação pode ser definida como a prática de comparar a massa e o teor médio de minério previstos pelos modelos geológicos com a massa e o teor gerados na usina de beneficiamento. Esta prática tem se mostrado cada vez mais importante, visto que, quando corretamente executada, aumenta a confiabilidade no planejamento de curto prazo e otimiza as operações de lavra e beneficiamento do minério. No entanto, a utilidade da reconciliação depende da qualidade e confiabilidade dos dados de entrada, gerados por diferentes métodos de amostragem. Uma boa reconciliação pode ser ilusória. Em muitos casos, erros cometidos em determinado ponto do processo são compensados por erros cometidos em outros pontos, resultando em reconciliações excelentes. Entretanto, esse fato mascara os erros do sistema que, mais cedo ou mais tarde, podem se revelar. Frequentemente, os erros de amostragem podem levar a uma análise errônea do sistema de reconciliação, gerando consequências graves à operação, principalmente quando a lavra alcança regiões mais pobres ou mais heterogêneas do depósito. Como uma boa estimativa só é possível com práticas corretas de amostragem, a confiabilidade dos resultados de reconciliação depende da representatividade das amostras que os geraram. Este trabalho analisa as práticas de amostragem manual em uma mina de cobre e ouro em Goiás e propõe um método mais confiável para fins de reconciliação. Os resultados mostram que a reconciliação aparentemente excelente entre mina e usina é ilusória, consequência da compensação de diversos erros devidos às práticas de coleta de amostras para o planejamento de curto prazo. / In the mining industry context, reconciliation can be defined as the practice of comparing the tonnage and average grade of ore predicted by the geological models with the tonnage and grade generated by the processing or metallurgical plant. This practice has shown an increasingly importance, since, if correctly executed, allows to improve the reliability on short-term planning and to optimize the mining and processing operations. However, the usefulness of reconciliation relies on the quality and reliability of the input data, generated by different sampling methods. Successful reconciliation can be illusory. In many cases, errors generated at one point of the process are offset by errors generated at other points, resulting in excellent reconciliations. However, this fact can hide compensating biases in the system that may surface someday. Very often sampling errors can be masked and may lead to erroneous analysis of the reconciliation system, generating serious consequences to the operation, especially when mining reaches poorer or more heterogeneous areas of the deposit. Since good estimation is only possible with correct sampling practices, the reliability in the reconciliation results depends on the representativeness of the samples that generated them. This work analyzes the manual sampling practices carried out at a copper and gold mine in Goiás, proposing a more reliable sampling method for reconciliation purposes. Results show that the apparently excellent reconciliation between the mine and the plant is in fact illusory, consequence of the compensation of many errors due to sampling practices for short-term planning.

While some prior studies document that investors overreact to information in sales growth as consistent with representativeness bias, other studies find no evidence of investor overreaction to either sales or earnings growth. Other recent studies also show that sales growth does not predict stock returns after controlling for changes in outstanding shares and asset growth. I reexamine the role of representativeness by investigating whether the effects of this bias are confounded by the presence of another effect that has been extensively documented - investors' underreaction to fundamentals. Adjusting for investor under-reaction to fundamentals, I document strong evidence that investors overreact to sales growth as predicted under representativeness despite adding accruals, asset growth, and equity issuance as additional controls. In cross-sectional regressions of future stock returns on predictive variables that control for fundamentals, changes in equity shares, accruals, and lagged 36 month returns, I find that the coefficient on sales growth is highly significant over both the full sample period 1970-2009 (t-stat -3.12). Furthermore, asset growth, equity issuance, and accruals lose much of their significance in favor of sales growth. I also provide evidence that rejects a theory based on fixation in favor of representativeness. These results document evidence of overreaction to past sales growth in firms where underreaction to fundamentals does not confound the overreaction due to representativeness bias.

No contexto da indústria mineral, reconciliação pode ser definida como a prática de comparar a massa e o teor médio de minério previstos pelos modelos geológicos com a massa e o teor gerados na usina de beneficiamento. Esta prática tem se mostrado cada vez mais importante, visto que, quando corretamente executada, aumenta a confiabilidade no planejamento de curto prazo e otimiza as operações de lavra e beneficiamento do minério. No entanto, a utilidade da reconciliação depende da qualidade e confiabilidade dos dados de entrada, gerados por diferentes métodos de amostragem. Uma boa reconciliação pode ser ilusória. Em muitos casos, erros cometidos em determinado ponto do processo são compensados por erros cometidos em outros pontos, resultando em reconciliações excelentes. Entretanto, esse fato mascara os erros do sistema que, mais cedo ou mais tarde, podem se revelar. Frequentemente, os erros de amostragem podem levar a uma análise errônea do sistema de reconciliação, gerando consequências graves à operação, principalmente quando a lavra alcança regiões mais pobres ou mais heterogêneas do depósito. Como uma boa estimativa só é possível com práticas corretas de amostragem, a confiabilidade dos resultados de reconciliação depende da representatividade das amostras que os geraram. Este trabalho analisa as práticas de amostragem manual em uma mina de cobre e ouro em Goiás e propõe um método mais confiável para fins de reconciliação. Os resultados mostram que a reconciliação aparentemente excelente entre mina e usina é ilusória, consequência da compensação de diversos erros devidos às práticas de coleta de amostras para o planejamento de curto prazo. / In the mining industry context, reconciliation can be defined as the practice of comparing the tonnage and average grade of ore predicted by the geological models with the tonnage and grade generated by the processing or metallurgical plant. This practice has shown an increasingly importance, since, if correctly executed, allows to improve the reliability on short-term planning and to optimize the mining and processing operations. However, the usefulness of reconciliation relies on the quality and reliability of the input data, generated by different sampling methods. Successful reconciliation can be illusory. In many cases, errors generated at one point of the process are offset by errors generated at other points, resulting in excellent reconciliations. However, this fact can hide compensating biases in the system that may surface someday. Very often sampling errors can be masked and may lead to erroneous analysis of the reconciliation system, generating serious consequences to the operation, especially when mining reaches poorer or more heterogeneous areas of the deposit. Since good estimation is only possible with correct sampling practices, the reliability in the reconciliation results depends on the representativeness of the samples that generated them. This work analyzes the manual sampling practices carried out at a copper and gold mine in Goiás, proposing a more reliable sampling method for reconciliation purposes. Results show that the apparently excellent reconciliation between the mine and the plant is in fact illusory, consequence of the compensation of many errors due to sampling practices for short-term planning.

Applied zooarchaeology provides baselines which can be used in modern conservation biology to better understand how faunal communities have changed over time. This goal can only be accomplished, however, by first accounting for the multiple biases present within the archaeological record, and how they may affect sample representativeness. Taxonomic analysis was conducted on freshwater mussel shell from the late prehistoric (ca. A.D. 700 - 1200) Kinlock site, Sunflower County, Mississippi. Species-area curves and biodiversity indices demonstrate that random sampling of surface clusters of shell, up to about 4,000 valves, provides an adequate picture of the overall surface assemblage. Comparison of surface and subsurface contexts shows a highly significant difference in species numbers and proportions, indicating a need for multi-context sampling when dealing with archaeological shell deposits.

This study examines individual-level citizen participation in the notice and comment component of federal agency rulemaking. It focuses on characteristics of individual participants ascertained through a survey mailed to 400 actual commenters. Survey data is used to evaluate the representativeness of these participants to the general public. Also, the compatible of citizen participation in rulemaking with the democratic ideals of liberty, equality, and fairness is evaluated, along with potential consequences of proposed reforms.

The key features of this dissertation pertain to limited investor attention and its indirect consequences of conservatism and representativeness biases that have impacts on the Taiwan Stock Market. Thus, this dissertation contributes to the empirical work on investors¡¦ limited attention and heterogeneous beliefs to public information, as well as representativeness heuristics. This study examines the market reaction of a sequential release of annual reports in Taiwan, in which different stages of attention-grabbing cause different market reactions. Moreover, investors with limited attention have an incomplete understanding about the content of the annual report, in which different years present significant positive or negative reactions of trading volume, and the evidence supports the hypothesis of limited attention. If people focus primarily on the strength of the evidence, they tend to neglect its weight and manifest representativeness bias. On the other hand, when people are unimpressed by the strength of the evidence, they focus too much on its weight and exhibit conservatism bias. Thus, this study distinguishes the behavioral biases between global representativeness bias and local representativeness bias. The results suggest that accounting performances globally have low strength but high weight features, leading investors to show conservatism bias, and other valuation ratios globally have high strength but low weight features, leading investors to exhibit representativeness bias. However, when global sequence is further decomposed into a local sequence, those behavioral biases disappear. This study also sheds light on how investors are sensitive to the streak length of performance, and the empirical evidence indicates that investors exhibit the gambler¡¦s fallacy to the trend of performance.

Prenatal and postpartum care are important for reducing maternal and infant morbidity. Racial and ethnic disparities are prevalent in maternal peripartum health and infant birth outcomes as well as peripartum care access and utilization. They highlight the need to identify and better understand correlates of poor prenatal and postpartum care compliance. While risk factors for low adherence to peripartum care have been identified, no studies have looked specifically at predictors of prenatal and postpartum care attendance in an at-risk sample of African American pregnant women. Using existing data from an RCT targeting maternal and infant health disparities and comparing a patient navigation/behavioral incentive intervention to treatment as usual, the present study sought to identify predictors of prenatal and postpartum care attendance. Participants were African American women at risk for poor prenatal care compliance, who participated in the RCT and had a documented live birth (n=123). Using hierarchical linear and logistic regression, the study identified predictors of prenatal and postpartum care attendance, respectively. The study found high-risk pregnancy (p < .001) and fewer barriers to care (p = .013) significantly predicted better prenatal care attendance. Less than adequate prenatal care attendance significantly predicted postpartum visit nonattendance (p < .001). In addition, given that study participants were limited to women who provided informed consent to RCT participation, the present study also examined representativeness of the clinical trial sample. Specifically, women who consented to the RCT (consenters; n=149) were compared to those who did not (non-consenters; n=122) on a variety of demographic and psychosocial variables using chi-square for categorical variables and t-tests for continuous variables. Consenters and non-consenters differed only on education level, with consenters more likely to have at least a high school education than non-consenters. The present study provides benchmark data on sample representativeness and predictors of peripartum care in a clinical trial of strategies to improve prenatal care compliance. These findings could have important implications for healthcare system changes and treatment interventions among this population.

Dans les gisements paléolithiques, les résidus anthracologiques étudiables sont parfois très abondants ou, au contraire, quasiment absents, sans relation évidente avec l’intensité des activités liées au feu. Ce constat pose la question de l’impact des processus post-dépositionnels, dont l’action est particulièrement importante dans les sites anciens. Lorsque la fraction grossière est rare, les charbons méso ou microscopiques sont souvent bien représentés, mettant en lumière un intense processus de fragmentation. Agent majeur de la formation des assemblages, la fragmentation conditionne le niveau de conservation du dépôt, mais aussi éventuellement la représentation quantitative des taxons. Dans une perspective méthodologique et au moyen d’une série d’expérimentation in vivo et in vitro (tests de compression, cycles gel-dégel, piétinement, retrait-gonflement du sédiment, etc.), les propriétés physico-mécaniques des charbons de bois et les modalités de fragmentation de différents taxons d’Europe tempérée sont caractérisées. Un ensemble de processus post-dépositionnels qui participent de la formation de nombreux dépôts du Pléistocène sont simulés de manière à mesurer leur impact sur le matériel anthracologique. Nos résultats montrent que les charbons de bois sont particulièrement sensibles aux processus météoriques et aux phénomènes périglaciaires ainsi qu’au piétinement. Le niveau de fragmentation des charbons laisse envisager l’ampleur des dommages causés sur la longue durée. Les propriétés physico-mécaniques et le comportement à la fragmentation des charbons de bois varient selon les essences. Ces différences s’expriment au niveau générique, spécifique et plus ponctuellement intra-spécifique, mais elles ne semblent pas de nature à induire des distorsions quantitatives majeures de la représentation initiale des taxons au sein des assemblages. Enfin, lorsque des différences entre taxons sont mises en évidence, elles s’expriment principalement au sein de la fraction fine (charbons compris entre 1 et 2 mm), laquelle est rarement étudiée en termes quantitatif. / Anthracological residues are often either very abundant or almost entirely absent in Palaeolithic sites, with no obvious relationship between their quantity and in the intensity of fire-related activities that may have occurred. This raises the question of the impact of post-depositional processes on anthracological residues, which is especially significant at ancient sites. When the coarse fraction is rare, meso and microscopic charcoal are often well represented, highlighting an intense process of fragmentation. As a major agent of the assemblages’ formation, fragmentation affects the level of conservation of the deposit, but also possibly the quantitative representation of taxa. From a methodological perspective and through a series of in vivo and in vitro experiments, the physico-mechanical properties of charcoal and the modalities of fragmentation of Europe temperate taxa are characterized. A set of post-depositional processes (freeze-thaw cycles, trampling, sediment shrinking and swelling, etc.), involved in the formation of many Pleistocene deposits, are simulated in order to measure their impact on anthracological residues. The results of this research show that charcoal is particularly sensitive to meteoric and periglacial processes as well as trampling. The level of fragmentation of charcoal makes it possible to consider the scale of damage caused over a long term exposure of the remains. The physico-mechanical properties and the fragmentation behavior of charcoal vary depending on the species. These differences are visible on a generic, specific and intra-specific level, though they do not seem to induce major distortions of the initial quantitative representation of taxa within assemblages. Finally, when differences between taxa are identified, they are mainly recovered in the fine fraction (charcoal between 1 and 2 mm), which is rarely studied in quantitative terms.